M67.30

Temporary, self-limiting inflammation of the synovial membrane at a joint site that is not specified in the clinical documentation.

Verified May 8, 2026 · 6 sources ↓

Status: Billable
Chapter: 13
Related CPT: 8
Region: General

Drawn from CDCICD10DataAAPCIcdcodesCMS

Documentation tips

What should appear in the chart to support M67.30.

Source · Editorial brief grounded in 6 cited references ↓

Identify the specific joint involved by name in every encounter note — hip, knee, shoulder, etc. — to avoid falling back to the unspecified-site code M67.30.
Document laterality (right or left) alongside the joint name to reach the most specific 7-character code available under M67.3x.
Record clinical findings that support transient synovitis: acute onset, self-limiting course, normal or near-normal ESR/CRP, absence of septic arthritis criteria, and imaging results such as ultrasound or MRI showing joint effusion.
Note the patient's age — transient synovitis disproportionately affects children, and age-concordant documentation strengthens coding defensibility.
If diagnostic imaging (ultrasound, X-ray, MRI) was ordered, link imaging findings directly to the diagnosis in the assessment and plan section.

Related CPT procedures

Procedure codes commonly billed with M67.30. Linking the right diagnosis to the right procedure is what establishes medical necessity.

Source · CMS LCDs · AAOS specialty guidance · claims-pattern analysis

20610 $68.81

Aspiration and/or injection of a major joint or bursa (shoulder, hip, knee, or subacromial bursa) performed without ultrasound guidance.

20611 $104.21

Aspiration or injection of a major joint or bursa performed under real-time ultrasound guidance, with permanent image documentation.

73502 $48.77

Radiologic exam of a single hip, capturing two or three views, including the pelvis when performed.

73521 $41.75

Bilateral hip X-ray examination capturing two radiographic views of both hips, including the pelvis when performed.

73560 $34.40

Radiologic examination of the knee joint, one or two views, unilateral.

27403 $610.57

Open arthrotomy of the knee with surgical repair of the meniscus performed through a direct incision into the joint.

29870 $602.89

Diagnostic arthroscopy of the knee, with or without synovial biopsy — a separate procedure designation meaning it bundles into any same-session surgical knee arthroscopy.

76881 View procedure details

Common coding pitfalls

The recurring mistakes coders make with M67.30 and adjacent codes.

Source · Editorial brief grounded in CDC ICD-10-CM tabular guidance, AAOS coding references, and cited references ↓

Using M67.30 when the joint is clearly documented elsewhere in the chart — always assign the site-specific subcategory (e.g., M67.351 for right hip) when laterality and location are available.
Confusing transient synovitis (M67.3x) with unspecified synovitis and tenosynovitis (M65.9) — M65.9 is for synovitis without a transient/self-limiting characterization; the clinical diagnosis drives which parent category applies.
Failing to check the Excludes1 note: palindromic rheumatism (M12.3-) cannot be coded with M67.3 at the same encounter.
Applying M67.30 to infectious or septic synovitis — infectious synovitis codes under M65.0x and requires an additional organism code; payers will flag mismatched diagnosis-to-treatment pairings.

Clinical context

Source · Editorial summary grounded in 6 cited references ↓

M67.30 applies when transient synovitis is documented but the affected joint is not identified anywhere in the encounter record. Transient synovitis is a self-limiting condition most frequently seen in children, classically affecting the hip, and typically presents with acute joint pain and limited motion. The unspecified-site designation here reflects a documentation gap, not a clinical category — the condition itself is joint-specific.

The M67.3x subcategory includes site-specific codes for shoulder (M67.31x), elbow (M67.32x), wrist, hip, knee, ankle, and foot, each with right/left/unspecified laterality options. M67.30 should only be used when the treating provider genuinely has not documented which joint is involved — for example, in a referral note or an incomplete chart. If the joint is documented anywhere in the record, assign the site-specific code instead.

The Excludes1 note at M67.3 bars coding palindromic rheumatism (M12.3-) at the same encounter. Do not confuse transient synovitis with infectious synovitis (M65.0-), which requires a separate code and has different treatment and payer scrutiny implications.

Sibling codes

Other billable codes under M67.3 (laterality / anatomic variants).

M67.38

Transient synovitis, other site

M67.39

Transient synovitis, multiple sites

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 6 cited references ↓

01When is it acceptable to use M67.30 instead of a site-specific M67.3x code?

Only when the affected joint is genuinely not documented anywhere in the encounter record — including the history, physical exam, and assessment. If the joint is named anywhere, assign the corresponding site-specific code.

02What is the most common clinical scenario for transient synovitis?

Transient synovitis most commonly occurs in children and typically affects the hip, presenting as acute unilateral hip pain and limp with a self-limiting course. For a documented right hip presentation, the correct code is M67.351, not M67.30.

03Can M67.30 be used alongside an infectious synovitis code at the same encounter?

No. If synovitis is infectious or septic, code under M65.0x with an additional organism code. Transient synovitis (M67.3x) is a distinct, non-infectious, self-limiting diagnosis — mixing these at the same encounter is clinically inconsistent and audit-prone.

04Does the Excludes1 note at M67.3 affect how M67.30 is used?

Yes. The Excludes1 note prohibits coding palindromic rheumatism (M12.3-) at the same encounter as any M67.3x code, including M67.30. These conditions cannot be reported together per ICD-10-CM tabular instructions.

05What CPT procedures are commonly billed with M67.30?

Joint aspiration or injection (20610, 20611) and diagnostic imaging such as plain films or ultrasound (73502, 76881) are the most common procedure codes paired with transient synovitis. Confirm payer LCD requirements — some require site-specific ICD-10 codes for imaging medical necessity.

06How does M67.30 differ from M65.9?

M65.9 (unspecified synovitis and tenosynovitis) is used when synovitis is diagnosed without further characterization. M67.30 requires the provider to have specifically characterized the synovitis as transient — meaning self-limiting in nature. The clinical diagnosis in the note determines which code applies.

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

Mira AI Scribe

Mira AI Scribe captures the affected joint name, laterality, clinical course (acute onset, self-limiting), ESR/CRP values, and imaging findings (effusion on ultrasound or MRI) from the encounter. That specificity drives the code from M67.30 up to a site-and-laterality-specific subcategory, preventing a payer downcoding flag and supporting medical necessity for any ordered imaging or aspiration procedure.

See how Mira captures M67.30 documentation